Fair Test Example

A Dirty Business

An advert on TV claims that a new brand of cleaner
is better than all the others. Your job is to design a fair
test to see if the claim is true.

Our
ideas:

Things we can change are:

The amount
of cleaner used

The temperature
of the water

The type
of cleaner

The amount
of water used

The type
of stains

The size of the stain

Things we can measure and record are:

The
time taken for the cleaner to dissolve stains

Sorting
our ideas

When comparing different cleaners, the one
thing we will change is:

The
type of cleaner

The one thing we will measure is:

The
time taken for the cleaner to dissolve stains

All these things we will keep the same:

The amount
of cleaner used

The temperature
of the water

The amount
of water used

The type
of stains

The size of the stain

Report
Writing:

We want to find out what things influence
the way that a cleaner dissolves stains.
In our test we will keep these things the same: The
amount of cleaner used, the temperature
of the water, the amount of water
used, the type of stains and
the size of the stain. We think that if we use the
TV brand cleaner, the measurements we record of the
the time taken for the cleaner to dissolve stainswill decrease.

What did I learn? I found out that the
TV brand cleaner does remove stains faster than the two other
brands we tested

I would like to know more about how
cleaning chemicals work and how "dry cleaning" works.

I enjoyed using the chemistry equipment.

I need help with tidying up afterwards.

The
Sorcerers Scientists Apprentice

Part One: Read this...

Scientists think of new ideas to explain what
happens around us. The idea is called a hypothesis. A scientists
will think "If I am right I can guess what will happen in
the future". This is called making a prediction. A good scientist
will always try to test their hypothesis to see if it matches
the prediction. The test must be done carefully so that it
is fair and honest. At the end of the test the scientists
thinks "What did the test show me?". This is called forming
a conclusion. Last of all, but most importantly, a scientists
asks "Do I need to change my ideas?"

Part Two: Copy and answer the questions
below:

What was your hypothesis? That the TV brand
cleaner would remove stains faster than the other brands.

What was your prediction? That it would take
less time for the TV brand to remove stains compared to
the other brands.

How did you try to carry out a fair test? By
only changing one thing at a time in our tests, and keeping
all other conditions the same.

What was your conclusion? The TV brand cleaner
is better at removing the stains we tested.

What did your conclusion tell you about your hypothesis?
My idea was correct.

NOTE:

An experiment is simply used
to TEST our ideas about the world around us.
Sometimes your conclusion shows that your original
idea was not correct. This is great!
You have discovered something you didn't know
before!

There is no single 'Scientific Method' that scientists
follow, but the above 'Fair Test' method is one way
to introduce the concept of objectively testing ideas
about the world around us.